ABSTRACT. In a 5-year-old Holstein cow, a neoplasm composed of a large intramuscular mass and multiple metastases in the lungs and lymph nodes was diagnosed as a pleomorphic rhabdomyosarcoma. This neoplasm was characterized by marked variation in tumor cell size and giant cells with single bizarre nuclei. Although the presence of cross striations and myoglobin could be confirmed, expression of alpha-smooth muscle actin (SMA) was also recognized in a few cells. Neoplastic cells showing intense staining for desmin, vimentin and proliferating cell nuclear antigen irrespective of their size differed from those in an embryonal rhabdomyosarcoma that exhibited a wide spectrum of differentiation, reminiscent of normal skeletal myogenesis. The cellular pleomorphism and SMA expression seemed to be characteristic of deviation from normal muscle cells or satellite cells in adult muscle.

Two imported male hooded mergansers (Lophodytes cucullatus) were introduced into a zoological aviary in Japan, and one of them died 10 mo later. Postmortem revealed numerous white yellowish nodules of various sizes in the liver. Two large nodules were also observed below the right lung and on the top of the left kidney. Histopathologically, a large number of tubercles with acid-fast bacilli were seen in the liver. The amyloid was deposited in the connective tissue of the tubercles. Bacteriologically, Mycobacterium avium serovar 1 was isolated from the liver.

ABSTRACT. A wild raccoon dog (Nyctereutes procyonoides) that manifested severe illness and died was examined. Necropsy revealed severe emaciation, systemic icterus and petechial hemorrhages on the mucous membranes. Histopathologically, necroses were seen in the liver and brain stem associated with meningitis. Eosinophilic intranuclear inclusion bodies were observed in the spleen and intestinal mucosa, and eosinophilic intracytoplasmic inclusion bodies were seen in transitional epithelium in the bladder. Listeria monocytogenes 4b was isolated from the liver, spleen, kidneys and lungs, and the pathogen was also detected in the liver and brain stem immunohistopathologically. The disease was diagnosed as listeriosis associated with canine distemper virus infection in a raccoon dog.-KEY WORDS: canine distemper, listeriosis, raccoon dog.

Salmonella typhimurium infection occurred in a children's zoo where 11 fowl and 85 mammals were kept. Initially, the guinea pigs were infected and transmitted the infection to the fowl and rabbits. These mammals responded to medication and cleared of the infection; however, the birds were judged to contain excreters despite four regimens of treatment with antibiotics. Cloacal swabs were taken from all the birds. One turkey was positive for Salmonella and was destroyed. Pooled fecal samples from the birds were again positive. All the birds were tested serologically, and two birds, a goose and a turkey, were positive with Salmonella pullorum-gallinarum antigen, which was assumed to be a cross reaction with S. typhimurium antigen. The two birds were destroyed and the goose yielded Salmonella. The infection was finally eradicated, and the serologic examination was considered to be the most useful procedure for detection of the excreters.

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